题目内容：

Go “back” in time

Is there a way to quickly recall（回忆）information just before taking an exam? Walking backwards might be a solution. Scientists from the University of Roehampton in the UK said this activity can help people improve their short-term memory.

Researchers asked 114 volunteers to watch a video. After watching the video, the volunteers were split（分成） into three groups. One group was told to walk 10 meters forward. The second group walked 10 meters backwards. The third group stood in one place. All three groups were then asked 20 questions about what they saw in the video.

The scientists found that the backward-walking group got two more answers correct than the other two groups.

This suggests that the link between the concepts（概念）of time and space is important in terms of how our minds form memories. “Time is really expressed via（通过）space,” Aleksandra, who led the study, told the Daily Mail. When you walk backwards, you see things from a different angle（角度） compared to walking forward, This difference helps people recall things that happened in the past.

And walking backwards is not just good for our brains. It is also good for the rest of our body. Compared to walking forward, walking backwards is more challenging. This can help us improve our fitness, according to New Scientist. Walking backwards uses more energy in a short time and burns more calories（卡路里）.

In addition, walking backwards is less stressful for our knees. It could be helpful for people who often have pain in their knees, according to researchers from the University of Oregon in the US. Walking backwards also keeps our spines（脊柱） strong, which can help to ease（缓解）pain in the lower back. This might be why many old people like walking backwards.

1.What does “this activity” in Paragraph 1 refer to（指的是）?

A. Recalling information. B. Taking an exam.

C. Walking backwards. D. Improving memory.

2.The second paragraph is written to         .

A. introduce a useful way of walking

B. show who can answer more questions correctly

C. explain why walking backwards improves memory

D. describe how researchers did their experiment

3.Which group got two more answers correct in the study?

A. The forward-walking group. B. The backward-walking group.

C. The standing-in-one-place group. D. All groups.

4.According to New Scientist, how can walking backwards be helpful?

A. It helps people remember information.

B. It allows people to see things in a new angle.

C. It helps people burn more calories.

D. It can ease pain in people’s knees and backs.

5.What do we know from the passage?

A. Walking backwards can help people in many ways.

B. Scientists suggest walking backwards for 10 meters every day.

C. Memories are formed when we do challenging activities.

D. Old people like walking backwards because it can help them lose weight.